class A {
  int count;

  A(this.count);

  @override
  String toString() {
    return "count$count";
  }
}

void main() {
  List<A> list = [A(1), A(2)];
  List<A> list2 = [];
  list2.addAll(list);

  print(list);
  print(list2);
  list[0].count = 3;
  print(list);
  print(list2);
}
